Cottonwood
Roadster#433, Model S#S37
Wow, in all, there are 30 grey map pins on the NA Supercharger map, after this refresh! Impressive. Just with these completed there will be 530+ supercharges in the world...
On top of that, there is a very good correlation between the gray pins and TMC tracking displayed reflected on supercharge.info
The gray pins not on supercharge.info should be good hints.